Plan the date of the event well ahead of time to give your volunteers enough notice so they can plan on being there.Sign up volunteers ahead of time, if appropriate have shifts. Have as many people working as possible as this attracts even more customers, with more potential for sales.Choose a suitable location – one that is centrally located, easy to get to, and preferably where there is maximum exposure. Make sure there is an outside water source where the hoses will reach. Fast food restaurants and supermarket parking lots are usually good ideas. Let people know that you are raising money for charity, and where the funds are going. Consider selling tickets in advance, maybe with “luxury service” like waxing, hovering, etc. Decide if you will be asking donations only or having a set price. Write this on your signs, and have a reasonable set price if using one. Additional services like window washing and tire cleaning can also be charged a set price. Set up a “drive thru” lane or two for speed and efficiency. People can then drive up a lane and get their cars washed quickly. Assign a volunteer to direct the cars and traffic.